This invention relates to endoscopic instruments, particularly to an intubation instrument, such as a laryngoscope.
Intubation of the human trachea is carried out daily in operating rooms and emergency facilities in order to facilitate respiration of a patient. The goal of the intubation process is to locate the distal end of an endotracheal tube in the larynx with the proximal end outside the patient""s mouth.
Safe and effective intubation requires controlled insertion of the endotracheal tube through a patient""s mouth so that the tube is directed to the upper part of the larynx, the glottis, without damaging or being blocked by the patient""s tissue. To this end, intubation instruments have been developed. Such instruments generally provide a somewhat rigid structure that is inserted into the mouth of the patient so that the distal end of the instrument is located in the glottis, adjacent to the vocal cords. An endotracheal tube is slid through the instrument during or after insertion of the instrument.
Advanced intubation instruments provide a lighted telescope or fiber optic viewing device. The telescope is carried by the instrument with the objective lens located at the distal end of the instrument and arranged so that the user may, via the proximal, viewing end of the telescope, observe the advancement of the instrument and the endotracheal tube. Such instruments are normally referred to as laryngoscopes.
In designing such intubation instruments it is important to provide a configuration that permits quick location of the instrument and tube without injurious or fatal delay that may occur with repeated attempts.
Precisely locating an endotracheal tube is certainly critical. Facial and neck trauma or the presence of blood, excoriation, mucus etc. may cause misdirection of the tube into the patient""s esophagus.
Common laryngoscopes offer an elongate, substantially straight blade portion having a distal end inserted through a patient""s mouth as previously described. Examples of such devices may be found in U.S. Pat. No. 4,360,008 to Corazzelli, Jr. (xe2x80x9cCorazzelli Jr.xe2x80x9d), and U.S. Pat. No. 5,827,178 to Berall (xe2x80x9cBerallxe2x80x9d). The geometry of these devices allow a practitioner to insert them while directly viewing the line of sight of the blade as it is inserted through a patient""s mouth and travels to the glottis. However, the path from the patient""s mouth to the glottis is not straight. Accordingly, during insertion of such laryngoscopes, the practitioner must physically manipulate a patient""s head, usually by pulling the patient""s head back to elevate the patient""s chin, in an effort to provide as straight of a path for receiving the laryngoscope as possible. Such manipulation is undesirable, particularly where the patient may have an injured neck or head. Moreover, the practitioner""s line of sight for inserting such straight devices is often blocked by interfering tissue and the like.
Inventor""s have attempted to overcome these problems with known laryngoscopes by attempting to improve the practitioner""s view during insertion. For example, Berall includes a camera mounted in the vicinity of the distal end of the blade and a viewer mounted to the laryngoscope, such that the practitioner has a simultaneous line of sight and camera view during insertion. However, such a camera view positioned toward the distal end is often unprotected from tissue and debris, and therefore becomes easily blocked. Moreover, such positioning is usually too close to offer the practitioner a helpful perspective to facilitate proper insertion and alignment of the laryngoscope and endotracheal tube within the larynx. Also, the straight blade remains difficult to properly insert.
Another attempted improvement to known laryngoscopes involves contouring the blade as shown in U.S. Pat. No. 5,800,344 to Wood (xe2x80x9cWoodxe2x80x9d), and slidably securing an image sensor along such a blade to facilitate viewing. However, to be properly inserted, such devices still require undesirable manipulation of a patient""s head and neck.
To facilitate insertion of these types of known laryngoscopes, some inventors have added moving tips to the blades as shown in Corazzelli, Jr. However, these tips are generally too small to adequately support the epiglottis, and they still require the practioner to insert an elongate straight or substantially straight blade, thereby required undesirable manipulation of the patent""s head and neck.
In addition, when cameras are inserted into a patient""s pharynx, the cold lense of the cameras combined with the moisture and heat of the pharynx tend to form fog or condensation on the camera""s lense, thereby rendering them useless. Efforts to prevent the fogging of these lenses during use have had limited success. For example, known defoggers include applying antifogging chemicals to the lenses of the cameras prior to insertion, or applying a spray of water onto the lense. These defogging options. can be time consuming and ineffective.
The present invention overcomes these and other problems of known intubation devices. It provides an intubation device that includes a configuration and arrangement of components that greatly facilitate rapid, safe placement of the instrument and associated endotracheal tube.
In accordance with one aspect of this invention, the instrument provides a blade or arm having an elongate base portion and an elongate lifter portion having a distal end thereof extending therefrom, preferably at an angle between 15xc2x0 to 85xc2x0, inclusive. The lifter is sized and shaped to engage, lift and support the patient""s epiglottis, thereby to expose the glottis.
In a preferred embodiment, the base portion and lifter portion are substantially the same length, and a viewing device, which is preferably a Charged Coupled Device (xe2x80x9cCCDxe2x80x9d) or Complementary Metal Oxide Semiconductor (xe2x80x9cCMOSxe2x80x9d) camera positioned near the transition portion between the base and lifter portions, is aligned to provide a perspective view toward the distal end of the lifter. Lights, which are preferably Light Emitting Diode (xe2x80x9cLEDxe2x80x9d) units, are positioned toward the distal end of the lifter to facilitate viewing. A transparent protective sheathing may be positioned over the assembly to facilitate cleaning and provide sterile multiple use of the device.
In an alternative embodiment, the lifter is pivotally secured to the base portion such that the optimal angle for a particular patient may be selected on site by the practitioner.
The instrument can also provide a path for guiding movement of the endotracheal tube in a manner that permits the distal end of the tube to move along the instrument directly toward the glottis. In such case, the instrument includes a passage into which a telescope is mounted. The arrangement of the guide path and passage ensures that the distal end of the tube remains observable as it is advanced to the glottis.
The observation of the movement of the instrument and tube is enhanced by the creation of a clearing at the distal end of the instrument. In this regard, the instrument includes structure for establishing a clearing at the distal end of the instrument, into which clearing the patient""s tissue is prevented from entering. The inner end of the viewing device is located at this clearing, as well as advantageously placed suction tube(s) for ensuring that the clearing remains free of fluid and vapor that would otherwise obstruct the operator""s view.
Moreover, a projecting guard is included for establishing the clearing. The guard is angled in a manner that permits smooth, sliding movement of the instrument across tissue to the desired, inserted position of the instrument.
In preferred embodiments of the invention, the instrument may include a second fluid passageway for delivering fluid to or from the distal end of the instrument. Moreover, the instrument can be configured to provide a channel for guiding secondary instruments, such as forceps, for clearly observed removal of foreign material in the larynx.
Also, a defogging element assembly may be operably secured to the instrument. The defogging element includes a heating element thermally-coupled to the lense of the viewer. The heating element heats when needed thereby warming the lense and preventing condensation or fog from forming on the lense.